State issues measles alert after Tarrant outbreak

The Texas health department issued a measles alert Friday after nine cases were confirmed in Tarrant County this week.

In all, 14 measles cases have been confirmed throughout the state this year, the most since 1996.

Dallas and Denton counties have reported two cases each, and Harris County has confirmed one.

“We have an outbreak” in Tarrant County, said Dr. Theresa Barton, associate professor of pediatric infectious diseases at UT Southwestern Medical Center.

“It concerns us because measles has the potential to be a really serious infection, which is why we vaccinate for it.”

No cases of measles were reported in Texas last year, and only six were confirmed in 2011.

“We issued the alert because most physicians probably don’t see this disease that often,” said Christine Mann, a spokeswoman for the Department of State Health Services.

The outbreak does not appear to be spreading between North Texas counties, health officials said.

Only those infected in Tarrant County were believed to still have active measles symptoms, said officials in the three North Texas counties.

“Of the new cases, the individuals who are currently ill and infectious have been asked to self-isolate,” Al Roy, a spokesman for the Tarrant County Public Health Department, said in a statement late Friday.

People with measles are considered infectious for seven to 18 days, starting four days before they develop a rash.

The Tarrant outbreak began when an adult traveled to a foreign country in late July and developed measles upon returning to Texas, officials said.

The first two cases were announced Thursday as being related to each other. The other seven were confirmed Friday.

“It has been determined that all of the new cases are connected to one of the previously known measles cases,” the Tarrant statement said.

“That one adult case [from the two originally reported] is the only one that has traveled outside the United States.”

The measles cases in Dallas and Denton counties occurred months ago but also were linked to foreign travel.

The Denton case involved a woman in her 40s who became infected in April while traveling in the Republic of Georgia, according to the Denton County Health Department.

After she was diagnosed, health officials notified the University of North Texas. She had attended an event there and may have exposed others, said Sarah McKinney, a spokeswoman for the Denton department.

The second measles case in Denton was linked to the woman in May.

The two Dallas County measles cases involved a 14-month-old child who traveled abroad and became ill in May, and a 14-year-old who was diagnosed in June.

The cases were related, said Dallas County officials, and no other contacts were found to be infected.

The statewide measles alert was intended to promote immunization against the highly contagious illness, which rarely is diagnosed because of high U.S. vaccination rates.

Of the nine cases in Tarrant County, “the vaccination status of these individuals varies,” Roy said.

How vulnerable the North Texas population might be in a wider measles outbreak is unknown. An estimated 98 percent of U.S. children have been vaccinated once by the time they’re 15 months old, according to the Centers for Disease Control and Prevention.

However, a second shot is needed to confer full immunity before a child goes to kindergarten. Many people, especially adults, did not receive the booster shot, UT Southwestern’s Barton noted.

“We do not have perfect vaccination rates,” she said.

The two-dose regimen also has about a 1 percent failure rate, the CDC says.

In recent years, some parents also have resisted childhood immunizations because of fears about children possibly contracting autism from the shots. One study purported to show such a connection but was later discredited.

“There has not been any established linkage between immunizations and autism,” Barton said.

Adults may be particularly vulnerable to contracting the measles because the booster shot was not recommended until the mid-1990s.

“Individuals born before 1957 are considered immune to the measles,” said Dr. Christopher Perkins, medical director of Dallas County Health and Human Services.

“But everyone should check their immunization records. Make sure your minor children, young adults and you yourself are all vaccinated.”